﻿using System;
using System.Net.WebSockets;
using System.Threading.Tasks;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
           
            Console.WriteLine("Hello World!");
        }
    }
    public interface IAddressService
    {
        string GetAddress(int contactNumber);
    }
    public class AddressService : IAddressService
    {
        public string GetAddress(int contactNumber)
        {
            string result = string.Empty;

            if (contactNumber == 123)
                result = "上海浦东";

            return result;
        }
    }
}
